Contradicting information on which oil to use

hey guys, I have a 15 Yukon SLT with 116k miles and have been told 2 types of oil to use. The dealer recommended synthetic blend while a local shop (Mavis) says full synthetic. Any suggestions?


Thanks!

I always use full synthetic--even on older cars. But both would work.

It really boils down to how much you want to spend. Full synthetic is better but more expensive.

Using the proper weight of oil and changing it as needed is more critical than if you should run syn-blend or full-syn. My preference is full synthetic. My opinion is that you can run anything including conventional, just for not as long as full-syn and you can run blend for a little longer than conventional, but not quite as long as full-syn. I'm not the authority on this, but I agree with the scientific conclusions that none of the options will match the long-term protection of fully-synthetic.

The dealer's gonna recommend whatever they wanna push. An independent tire/lube place is gonna recommend whatever makes the biggest sale. Go with the best you can afford to stick to and alter your oil change intervals accordingly. My generalized rule of thumb (without doing all the specific math) is that synthetic costs about twice as much as conventional, but it can safely be used for twice as long, so the cost balances out. But, synthetic provides better protection throughout it's life over conventional, and that's what really matters so it's a clear winner for me. The half as frequent oil changes is a plus as well.

When I first got my 16 Hoe it had Synthetic Blend in it.. At 5K miles I switched it over it 0w20 Mobil 1..Have been using nothing but Mobil 1 for years in all my other vehicles..Plan on using nothing but Mobil 1 0w20 in my Hoe..I change out every 5-6K miles..I use either Mobil 1 AFE or Mobil 1 EP..The Mobil 1 EP is next to impossible find in my neck of the woods.

All that just IMHO.

Chevrolet's Dexos oil is now full synthetic. We put it in every 2011 model up.

Full - while you are in there doing the oil change it doesn't make sense to economize on oil type to save $10. Put the best oil in using the specified viscosity and change interval. Read the AAA independent report on conventional vs. synthetic oil.

Whatever you do, my experience has convinced me to never trust the computer estimate of oil life. Never look at that as being the barometer for oil change time. Change whatever you use at regular intervals regardless of the computer reading. I'd do every three thousand for conventional. Every 4500 for blended synthetic. Every 6,000 for full synthetic. I grew up in the old days back when back in the sixties we changed our oil and filter every 2000 miles, religiously. Every 3000 if most of the driving was highway cruising. But I even change the GM blended stuff at 3000 to 3500 because of problems in our 2008 Tahoe Hybrid 6.0 L at 86,000 miles. I did not know she was putting 7500 on the oil because the dealership told her it was OK to run it down to 20% on the computer. Bad deal and expensive. But is is still running fine and using no oil with 138,800 on the clock and consistently getting 21.1 on the computer mileage overall reading, between 20.7 and 21.9 normally actual computation. Best ever was a couple months ago at 23.6 for some reason. Probably after I added a can and a half of Berryman's B12 Chem Tool.

Good points Bruce. I've been changing when I get to 20% or so. I should check the mileage. I agree that full syn. should be changed at 6-7k miles. I think Subaru just reduced the change interval to 7k for full syn.

Full Syn all the way. There are no disadvantages besides initial price which makes it cheaper in the long run. Invest more in the beginning, save later. Time is money. Oil filters arent free either. Even if you could use same oil filter for 2 oil changes, I wouldnt want to. The only reason I would use conventional is fear of oil leaks on older high mileage engines (assuming engine has been drinking conventional all its life.)

Meccanoble said:

Full Syn all the way. There are no disadvantages besides initial price which makes it cheaper in the long run. Invest more in the beginning, save later. Time is money. Oil filters arent free either. Even if you could use same oil filter for 2 oil changes, I wouldnt want to. The only reason I would use conventional is fear of oil leaks on older high mileage engines (assuming engine has been drinking conventional all its life.)

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Yea switching to synthetic is perfectly acceptable. Changing the oil filter every second oil change is a bad decision, under all circumstances. All street automotive engines have an oil bypass where the oil will 100% bypass the filter when the filter gets plugged enough. As long as you stick to the recommended viscosities, including the winter rating synthetic won't leak much more than conventional oil.